title: Horizontal and vertical eye movement metrics: what is important?
abstract: OBJECTIVE
  To assist other eye movement investigators in the design and analysis of their studies.
  
  
  METHODS
  We examined basic saccadic eye movements and smooth pursuit in the horizontal and vertical directions with video-oculography in a group of 145 healthy subjects between 19 and 82 years of age.
  
  
  RESULTS
  Gender and education level did not influence eye movement metrics. With age, the latency of leftward and vertical pro- and antisaccades increased (p<0.001), velocity of upward prosaccades decreased (p<0.001), gain of rightward and upward prosaccades diminished (p<0.001), and the error rate of antisaccades increased (p<0.001). Prosaccades and antisaccades were influenced by the direction of the target, resulting in a right/left and up/down asymmetry. The skewness of the saccade velocity profile was stable throughout the lifespan, and within the range of saccades analyzed in the present study, correlated with amplitude and duration only for antisaccades (p<0.001).
  
  
  CONCLUSIONS
  Some eye movement metrics must be separated by the direction of movement, others according to subject age, while others may be pooled.
  
  
  CONCLUSIONS
  This study provides important information for new oculomotor laboratories concerning the constitution of subject groups and the analysis of eye movement metrics.
authors.affiliation: Dept. of Neurology and Centre of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic. Electronic address: bonnet.cecilia@gmail.com.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bonnet
authors.forename: Jaromír
authors.initials: J
authors.lastname: Hanuška
authors.forename: Jan
authors.initials: J
authors.lastname: Rusz
authors.forename: Sophie
authors.initials: S
authors.lastname: Rivaud-Péchoux
authors.forename: Tomáš
authors.initials: T
authors.lastname: Sieger
authors.forename: Veronika
authors.initials: V
authors.lastname: Majerová
authors.forename: Tereza
authors.initials: T
authors.lastname: Serranová
authors.forename: Bertrand
authors.initials: B
authors.lastname: Gaymard
authors.forename: Evžen
authors.initials: E
authors.lastname: Růžička
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004585:Electrooculography / Q000379:methods*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011698:Pursuit, Smooth / Q000502:physiology; D011930:Reaction Time; D012438:Saccades / Q000502:physiology; D055815:Young Adult
keywords: Antisaccades; Eye movements; Eye tracking; Normative data; Prosaccades; Skewness; Smooth pursuit